1. Field of the Invention
This invention relates to a parts mounting method and a parts mounting apparatus using a suction section provided with a plurality of suction nozzles for sucking parts stored in a parts supply section onto the suction nozzles of the suction section and mounting the parts on a board with high accuracy.
2. Description of the Related Art
Some electronic parts mounting apparatus for automatically mounting electronic parts on a printed board, etc., each includes a movable suction section provided with a plurality of suction nozzles to suck and hold electronic parts. In this kind of electronic parts mounting apparatus, the suction nozzles and parts supply sections of electronic parts are spaced uniformly and thus when the electronic parts are sucked, it can be expected that all suction nozzles are moved up and down for sucking the electronic parts at the same time with the suction nozzles for improving productivity.
As shown in FIG. 14, in this kind of electronic parts mounting apparatus 1, a move head 3 of a suction section is movable on an X-Y plane and a plurality of (for example, eight) suction nozzles 5 mounted on the move head 3 can be moved up and down and rotated separately. The move head 3 is moved to a parts supply section 7 and electronic parts are sucked to the suction nozzles 5. The suction attitude of each sucked electronic part is recognized in a parts recognition section 9. The attitude of each electronic part is corrected based on the recognition result. On the other hand, in the electronic parts mounting apparatus 1, a printed board brought in from a transport unit 11 is positioned to a predetermined position and the electronic parts whose attitude is corrected are mounted in order at predetermined positions of the printed board.
When the suction nozzles 5 are placed at equal intervals to the parts storage pitch in the parts supply section, if the first suction nozzle 5 is at a position where it can suck a part, it is also made possible for the second to fourth suction nozzles 5 to suck other parts.
However, the electronic parts mounting apparatus 1 cannot make position correction at the parts suction time for each of the suction nozzles 5 and can make position correction only in the move head 3 unit and thus if the shift amount between the center of the suction nozzle 5 and the center of the electronic part is not corrected, only large-sized electronic parts that can be sucked comparatively stably are sucked at the same time.
In recent years, with size and weight reduction of an electronic machine, resistors and capacitors of minute size called 0603, 1005, etc., for example, have been becoming the mainstream of chip-like electronic parts, and the demand for simultaneously sucking such minute electronic parts also rises for the purpose of improving productivity.
However, the electronic parts mounting apparatus in the related art moves the whole suction section, thereby correcting the shift amount at the parts suction time. Thus, large-sized electronic parts for which the shift amount between the center of the suction nozzle and the center of the electronic part need not be corrected can be sucked at the same time, but minute electronic parts for which the shift amount caused by the dimension tolerance, parallelism, etc., of the parts supply section and the nozzles needs to be corrected for each suction nozzle cannot be sucked at the same time because the nozzle center may shift largely from the center of the minute electronic part.
In contrast, if each suction nozzle is provided with a linear motor, etc., and is enabled to move in an XY direction and correction can be made for each suction nozzle, it is also made possible to suck minute electronic parts at the same time. However, if such a mechanism is adopted, the suction section becomes upsized and complicated and is increased in costs; it is not realistic.
It is therefore an object of the invention to provide a parts mounting method and a parts mounting apparatus for making it possible to use suction nozzles similar to those in a related art to simultaneously suck even minute parts formerly unable to be simultaneously sucked unless correction is made for each of the suction nozzles and improve productivity of mounting parts.